Based on the insights in Dr. Weil's bestselling book, "Healthy Aging," this plan is an interactive, dynamic online source of information that can help anyone successfully negotiate the process of growing older.

Here’s one less thing to worry about as you get older: your immune system will still be as capable of shaking off bugs as that of a much younger person. A study at Canada’s McMaster University assessed the resistance of individuals under 40, between 41 and 59 and older than 60 when infected with three different viruses, including West Nile, and found that the study’s seniors demonstrated perfectly normal immune responses. Their T cells, an important class of immune cells, responded to the virus with the same vigor as T cells from the study’s younger participants, the researchers reported. Jonathan Bramson, Ph.D., the study’s principal investigator said that it had been thought that seniors were at higher risk of infections because they had fewer numbers of these immune cells or that they weren't as active, but that the study demonstrated that “the elderly are certainly capable of developing immunity to viruses.” The researchers reported that the number of virus-fighting T cells and the function of those cells “were equivalent in all three groups.” The study was published in PLOS Pathogens on December 13, 2012.